Metallurgical furnace.



U. WEDGE.

METALLURGICAL FURNACE.

APPLICATION FILED JAN. 4, 1 913.

Patented Mar. 30, 1915.-

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METALLURGICAL FURNACE.

Patented Mar. 30, 1915.

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UTLEY WEDGE, OI? ARIDMORE, PENNSYLVANIA.

METALLURGICAL FURNACE.

Specification of Letters Patent.

Patented Mar. 30, 1915.

'Applicationfiled January 4, 1913. Serial No. 740,104.

To all whom it may concern:

Be'it known tha I, UTL'EY'WEDGE, a citi zen of the United States,residing in Ardmore, Pennsylvania, have invented certain ImprovementsinMetallurgical Furnaces, of which the following is a specification.

' My invention relates to that type of furnace having its hearth orseries of superposed hearths surrounding a central rotat-' ing shaftwhich usually carries projecting arms provided with depending rabblesfor stirring and feeding the ore or other ma terial deposited upon thehearth or hearths of the furnace, my invention providing for thethorough heating of said material without unduly heating the rabble armswhen the same are employed, permitting the use of either gas, oil, or anelectric current as the heating medium, and providing simple andeffective means for the use of the electric current as such heatingmedium.

In the accompanying drawings-Figure 1 is a transverse vertical sectionof part of a superposed hearth furnace of the type to which my inventionrelates, illustrating one method of using oil as the medium for heatingthe treating chamber ofthe furnace;

Fig. 2 is a similar View illustrating means for employing gas as theheating medium; I

Fig. 3 is a view similar'to Figs. 1 and 2 but illustrating a means ofemploying an electric currentas a heating medium; Fig. 4 is. a her5011... section of the furnace on the line a/a, Fig. 3, and Fig. 5 is atransverse section, on an enlarged scale, on the line b-b, Fig. 3.

In Figs. 1, 2 and 3 of the drawing, 1 rep resents the outer wall, 2 theroof, 3 thetop hearth and 3 the top treating-chamber of a furnace of thesuperposed hearth type to which my invention is particularly adapted,although it may, if desired, be applied to a furnace having but a singlehearth and a single treating chamber.

The hearth 3 and treating chamber 3* are annular and surround a centralshaft,

which, by preference,consists of a metallic cylinder .4 provided with asuitable covering of refractory material 4' to protect it from the heat.This shaft is combined with any available means for causing rotation ofthe same, as for instance the means shown in my Letters Patent No.777,577, dated December 13, 1904.

Secured to the shaft and projecting radially therefrom into the treatingchamber 3 are a pair of diametrically opposite rabble'arms 5 which areintended to be provided, in the ordinary manner, with depending rabblesfor stirring and feeding the material on the hearth 3, as the shaft 4 isrotated. Also mounted upon the shaft 4 and rotating therewith are a pairof oil burners 6, which are, by preference, diametrically opposed anddisposed at right angles to or midway between the rabble arms 5, theseoil burners receiving their supply of oil from a tank 7 at the top ofthe shaft and also receiving a supply of steam or air under pressurethrough branches 8 from a central pipe 9, which rotates with the shaftand has, at the top, a suitable stuffing box connection with the fixedsupply pipe 10 above the shaft.

The flame from the 'burners 6 is projected outwardly across the annulartreating chamber 3 and comes directly into contact with the materiallying upon the hearth 3, and, as the shaft 4 and the burners 6 rotate,the jets of flame are carried around over the entire hearth and allportions of the material lying upon the hearth are therefore subjectedto the action of the flame.

In the construction shown in Fig. 2 the heating of the treating chamber3 is effected by a jet of gas from a burner 11 or by downwardly directedjets from a pipe 12 projecting into the treating chamber, the centralgas pipe 13 communicating with the fixed gas pipe 14 above the shaft andbeing in communication with the burner 11 by means of a branch pipe 15and in direct communication with the pipe 12.

In the construction shown in Fig. 3 an electric current is used as theheating medium, arms 16 projecting into the treating chamber from theshaft 4 which arms are segmental in cross section, as shown in Fig. 5,and cary an electrode 17 which is mounted in a ring-like portion of theouter end of the arm and in an insulating bushing 18 at the innerend ofthe arm. Rings 19 and 20 are mounted upon the upper end of the shaft 4so as to be insulated therefrom and from each other, the ring 19 beingin contact with a brush '21, which is connected to one pole of anelectric generator, and the ring 20 being in contact with a brush 22,which is connected to the other pole of said generator... The ring 19 isconnected by wires 23 to each of the arms 16 and the ring 20 isconnected by wires 24 toeach of the electrodes 17, consequently electriccurrent is caused to flow from the ring 19 through the wire 23 to thearm 16 and thence back through the electrode 17 and wire 24 to the ring20. The electrodes 17 being of resisting material becomes highly heatedand radiates its heat onto the material lying upon the hearth of thefurnace. By reason of the mounting on the electrode 17 on the under sideof the arm 16, said electrode can approach closely to the surface of thematerial lying upon the hearth and the concave form of the arm above theelectrode serves to dedeflect heat onto the material and prevents itfrom being radiated into the upper portion of the treating chamber,consequently the structure described provides for economical operationand'constitutes one of the features of my invention.

The sheets of flame from the burners 6 of Fig. 1 and from the burners 11and 12 of Fig. 2, and the heated electrode 17 of Fig. 3 are allrelatively remote from the rabble arms, consequently the latter are notexcessively heated and the rapid burning out ofthe arms or otherinjuries thereto due to excessive heat are thereby prevented.

To prevent excessive heating of the arms 16 the latter may have linings28 of material which is a non-conductor or a-poor conductor of heat, orthe arms may also be cooled by a flow of water or other cooling fluidthrough the same, as is common in rabble arms, or both of these methodsmay be adopted.

I claim:

1. The combination, in a furnace, of a central rotating hollow shaft anda hearth surrounding the same and-having above it 1 a closed treatingchamber, said hearth and chamber being in close relation to the shaft,rabble arms and heating devices carried by and rotating with said shaft,said heating devices being disposed at points remote from the rabblearms, and means disposed within said hollow shaft for conveying theheating, agent to said heating devices.

2. The combination, in a furnace, of a central rotating shaft and ahearth surrounding the same, with an electrical heating device carriedby and rotating with the shaft and having an electrode projecting overthe material upon the hearth of the furnace.

3. The combination, in a furnace, of a central rotating shaft and ahearth sun-- rounding the same, with an electrical heating devicecarried by and rotating with the shaft, and comprising an arm projectingover the material on the hearth of the furnace and having on its underside an elec trode to be heated by the passage of the electric current.

4. The combination, in a furnace, of a central rotating shaft and ahearth surrounding the same, with an electrical heating device carriedby and rotating with the shaft and comprising an arm of segmental crosssection projecting from the shaft over the material on the hearth andcarrying upon its under or concave side an electrode to be heated by thecurrent.

5. The combination, in a furnace, of a central rotating shaft, a hearthsurrounding the same, and an electrical heating de vice comprising anarm projecting from the shaft over the material on the hearth, anelectrode carried by said arm and in conducting contact With the same atone end, means for insulating the electrode from the arm except at suchpoint of contact, means for connecting the arm with one pole of theelectric generator, and means for connecting the electrode with theother pole of the same.

6. In a mechanical furnace provided with a revolving shaft carrying arabble arm, a burner having a flame opening at its end carriedsubstantially radially by said shaft.

7. In a mechanical furnace provided with a hollow revolving shaft,carrying a rabble arm, a burner carried by said shaft, located at apredetermined distance in advance of said rabble arm.

8. In a mechanical furnace provided with a hollow revolving shaftcarrying a rabble arm, a burner carried substantially radially by saidshaft, located at a predetermined distance in advance of said rabblearm.

9. In a mechanical furnace provided with a hollow revolving shaftcarrying a rabble arm, a plurality of burners, having flame openings attheir ends carried substantially radially by said shaft, said-burnersand the flames thereof being out of contact with said'rabble arm.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

UTLEY WEDGE. Witnesses:

KATE A. BEADLE, HAMILTON D. TURNER.

Copies. of this patent may be obtained for five cents each, byaddressing the Commissioner 0! Patents,

Washington, D. G.

